1. Field of the Invention
The present invention relates to a novel reactive dyestuff, more particularly, to a novel reactive dyestuff that is suitable for exhaust dyeing, cold batch-up dyeing, continuous dyeing, printing and digital spray printing materials that contain hydroxyl group or polyamine fibers.
2. Description of Related Art
An azo dyestuff, where the chromophore thereof is composed of azo components and coupling components, can be widely employed and used as a reactive dyestuff for heavy color dyeing, such as red, navy, blue, black and so on, owing to its board color gamut and high extinction coefficient. Among azo dyestuffs, a navy reactive dyestuff with sulphato-ethyl-sulphone (SES) groups produced in 1957 by Hoechst in Germany, C.I. Reactive Black 5, is the most well-known. C.I. Reactive Black 5 can be used to dye fabrics intensely heavy shade and its structure is represented by the following formula (A).

The reactive dyestuff has been applied in the dyestuff industry for many years. Currently, the development of reactive dyestuffs moves towards higher fixation and better build up to meet the economic demands. Over the years, many researches focus on the development of dyestuffs that show better build up to meet the economic demands in comparison to C.I. Reactive Black 5. For example, in 1980, Hoyer et al. in Hoechst disclosed a tetraazo structure with a sulfonyl bridge group in U.S. Pat. No. 4,244,258. The tetraazo structure is represented by the following formula (B).

In 1997, Tzikas et al. in CIBA Geigy disclosed a tetraazo structure with an aminocarbonyl or aminosulfonyl bridge group in U.S. Pat. No. 5,629,410. The tetraazo structure is represented by the following formula (C).

However, the build up, hue-shift, levelness and wash fastness of the aforementioned novel dyestuffs cannot meet the market requirements. Thereby, it is desirable to improve the aforementioned properties.